Hardened material for use in the arts as substitutes for diamonds



A. J. LIEBMANN AND C. A, LAISE. HARDENED-MATERIAL FOR USE 1N THE ARTS AS SUBSTITUTES FOR DIAMONDS, 81.0., AND

PROCESS OF MAKiNG THE SAME; APPLICATION FILED MAY 5. i9 17.

Patented June 22, N20

3 SHEETS-SHEET l.

. A. J. LIEBMANN AND C. A. LA|SE.'

HARDENED MATERIAL FOR USE IN THE ARTS AS SUBSTITUTES -FOR DIAMONDS, 840., AND

PROCESS OF MAKING THE SAME; APPLICATION FILED MAY 5-I9I7.

1,3433%, I A PatefltedluneZZ, 19206 3 SHEETSSHEET 2.

mmz um' v son,

.. costly and it has there yery near .q embbdying our invention v ar A jjfor use as dies for-,the'drawin ALFRED J. mnnmmun, or NEW YORK, N.

PATE T 0am.

Y., AND CLEMENS- LAISE, or WEE-- HAWKEN, NEW JERSEY, ASSIGN ORS, BY MESNE ASSIGNMENTS, I'O INDE- PENDENT LAM]? A'ND WIRE COMPANZY, INQ, OE NEW' YORK, N. Y., A COR- r ona'rroiq or new. JERSEY.

HARDENED MATERIAL l v x To all whom ct may concern: 0

Be it knownthat we, ALFRED J L a-e- MANN and GLEMnNs A. LAIsE, citizens of the United States, and residents, respectively, of the .boro fii of Manhattan, city and State oi New Yor and Weehawken, county of Hud- State of New Jersey, have invented certain new and useful Improvementsin Hardened Material for Use in the Arts as Substitutes for Diamonds, &c., and Processes of Making the Same, of which the following is a specification.

' rystallized carbon, or the d amond, 1s I the hardest of all knownrsubstances'and on account of its extreme hardness a diamond is used in the technical world in many relations where a substance of extreme hardness is required. For, instance, diamonds or sapphires are used for the ewels 1n watch movements, and also in electrical instru- 1 ment s,'for nstance volt meters, ammeters or watt-meters.

The diamond is also useful for the drawing of wires of all description and for lass cutting. It is also useful in powdereif-formfor polishing and grinding, anda's an abrasive. I p I Bedause' of' its rarit the diamond is ore been the desire of those interested to produce the diamond artificially, and-while this result has been accomplished .itfhas only been done on a laboratory. scale. p

Wehav invented ess of making the same, which material for all practical purposes may be used in the. arts in the place of the pure diamond, and while it is not actually as hard as the pure diamond, it isalmost as hard and can be readily produced;0n a laigescale. We. have also invented'a methgd' "of producing a umber of materials which are the ydiamon'd j and sapphire m hardness and which can be produced oom-. mercially in the different forms and shapes which are useful. for applieatig in/thef-arts as' above outlined. H

I As hereinabOVeTeferred to, t1

a .asubstitute for the jewels-o i ron use In THE ARTS AS sunsrrru'rns For. AND rnocnss or MAKING THE SAME. 1

Specification 'of Letters Patent.

the rinciple ofour' invention. V e have discovered a material a proc- 1 iiuiiyplatinem,

it ter'described l --"--We have further discovered thatthe prodmmomps, &c.,

' Patented June 22 1920.

' Application filed May 5, 1917. Serial No. 166,688.

ments and in electrical measuring 'nstruments, and for many other similar 'p poses.

The' substances embodying our-invention.

are also use'fiil .andeifective for the ham-- mering or working surfaces of hammering dies or punching dies; as plates; or the working surfaces of lates where great hardnessds required; or the manufacture" of instruments requirin very sharp edges and as an abrasive eit er. alone or mixe with other substances, in powder form 'or compressed in the shape of or stones tobe used as grinding stones forgrinders,fshapers, cutters or the like.

The principal constituent of the product of our invention is preferably the metaltungsten which in itself. is a material' of great. hardness Instead ,of tungsten, we have succeeded in makingvery satisfactory products by using the metal mol :bdenum, and also a mixture or 'alloy of't e metals tungsten and molybdenum.

In the interest of clearness will .be limited to the refractory. metal tungsten alone, it of course being understood that when the tungsten is hereinafter mentioned other high, fusing or refractoryture or alloy 'of tungsten and mol bdenum may be substituted without depart ng from stenywhen properly prepared as hereinafter lates, Wheels the description l I that the metal t un'gdescribed, andcemented'or carbonized,,pro-

duce's a material which was .l e'ret'ofore unknown and which has desirable properties adapting enumerated.

Our new alloyconsists of either ppre- 90.- .F l -s fi r titanium, boron, 11011, s licon, mckelyphrom thorium zirconium,

tungsten or ure molybdenum, or a or. alloys t ereof, combined? with carbonor the taxi or the'aboiienien tioned metals,- eitiie rj with carbon'separa't'el or incombi-natiofis such as will be hereina 7 itfor the "uses in' the arts above 7 i lictsefaour invention notonly s'erve'the 'pur- ,workingof metallic materials while cold, but also that they are'especially suitablefor the 'working of metallic materials whilehot.

The principal points or features of our invention relate to a process of combining the cementation and. alloying of refractory materials such as tungsten or molybdenum.

This may be done by taking the pure metal elements and treating them at high temperature while-"the elements are in contact with carbon or aycarbona'ceous vapor and oxids of boron or rare earth. By, thls method a 1 carbonaceous atmosphere 1s created around the metal and simultaneously .a vapor f .metals or metallic oxids is also created around the metal. These vapors and the carbonaceous atmosphere produce both a cementation effect or a carbid forming effect,

and an alloying effect, and at the same time or body from this mixture and subjecting it to a high temperature, preferably. in acar- 1 bonaceous atmosphere, which may be created by heat treatment of the carbon present or directly, by passing car-bon monoxid or carbon dioxid gas into the treating space while the electrodes. are at high temperatures.

Usually when the bodies to be treated are of considerable sizethe operation iscarried out by conducting a carbonaceous gas around the objects. If, however, the objects are small they may be placed between carbon or. graphite electrodes and the heat which is generated while sending the current through them is 'suflicient t'o'autom'aticall'y lug, lO-a screw for securing it to the upper .produce a carbonaceous atmosphere.

In the reaction which takes-place in these processes we have the combined effectof a carbon Vapor and .a metallic vapor, or an oxid vapor-.or botlYi- The resulting product isdue to the fact that there is cementation between the carbon and the metals, a combinationbetween the metals and the bxids and an alloying between the metals.

The accompanying drawings show a mechanism which is useful in carrying out our v process.

- outour invention.

Referring to the drawings in which the samereference character indicates the same part in theseveral views; e

Figurel is a side elevation with partsbroken away and others in section of a mold or press wh1ch may be utilized incarrying Fig.2 is a plan view of the press shown in Fig. 1. I 4

Fig. 3 is an elevation with parts broken away and other parts in section, and other parts shown diagrammatically of a treating T I r the mechanism under a bell jar.

In the drawings, referring to Figs. 1 and '2, 100 represents the molding blocks, 100

inFi .6.

represents cross strips arranged on either side of the blocks; 200' bolts passing through the ends of'the cross strips; 200, nuts on the bolts for forcing the cross strips and the 'moldin blocks together.

a The aces of the molds are provided with semi-circular grooves which when the molding blocks are held together, form a cylindrical cavity. In the lower portion of this cavity is situated a forming key 700, and in the. upper portion a pressing rod 500. A I

disk 600 represents the materialto be compressed between the forming key 700 and the pressing rod 500. 800 represents adjusting screws impinging against the side of the block 100, and which when adjusted facilitates the removal of the pressing rod 500. Guide-pins p are shown in the molding blocks by means of which .the blocks are held in position. Referring to Fig.3, 1 is an'A. 'C. generator; 2 a switchin theprimary circuit; 3

'a transformer; 4 a rheostat, 5am ammeter,

6 a volt meter, 7 a single ,poletswitch 'and 8 a flexible stranded connection for the wire 8'. The circuit is'completed by the wires 8 8 and 8 as shown. 9 is a cable electrode holder '11, which holder slides in guides 29 and 30. A pin or rod 31 projects from the upper electrode holder into a slot in the end of the lever 32, the opposite end of which is'connected to the rod 33 for connecting the lever to the treadle,

nobshown. The guides 29 and 30 are secured in any suitable way to standards or columns 24, 25, 26 and '27, held inplace by thenuts 28. The upper electrode12 is secured in any suitable way to the electrode holder 11,,as by a clamp consisting of two parts 15 and 11 pivoted toleach other at 10. At the opposite end of the part 115 is pivoted a rod 16'at 40,- the rod fitting between openjaws 'in the end of'the part 15 of the clamp, the two free ends being forced together by means of the wing nuts 17 engaging the screws on the-rod ld so as to efiectually hold the electrode 12 to the electrode holder 11', all as clearly shown which 18 and the-base. 23. 21 is an insulating,

e the upper surface of-the "proximately eight inches long,

' frame and lower electrode 18 which are con- Washer. 22- is a collar secured to the holder 18 to support the insulating washer. 13

'is the lower electrode which is secured'in place by the wing nut 17 and clamp 15, said wing nut being operative on the screw bolt 16, "14 is the disk of materialtobe hardened and 7;. represents powdered hardening material placed innthe cavity 13' in electrdde 13, Powdered hardening material k may also be inserted in a cavity, as shown, in the upper surface of the disk 14. 1 i V In Fig. 4 the disk 14 to be operated upon is held 1n the cavit in the upper surface of the lower electro e 13 and no hardening material is used externall f In Fig.5 the material to beoperated' upon is formed in the shape of a rod ap and this rod .is also held in the cavity 13' in the lower electrode.

In 'Fig. 7 we have shown diagrammatt cally, the treating apparatus showing the upper electrode holder 11, the supporting nected together ,electrically as indicated, a 1 table 34: having a 'groove 34 in the top thereof into which fits the edges of the bell jar J. Suitable inlet and outlet ports P, P

are arranged in the bell jar the lower port P for the entrance of heavy gas, when used, and the upper-port P being the exit port, whereas if light as is used it enters through the upper port and the exit port is then the lower portP.

It is, of course',-'to be understoodthat these drawings are merely. illustrative-and more or less conventional, showing- 1n a general way the construction of. the mold and the construction of the'trating. ma-

" chine which we contemplate using in the carrying out of our new process 'andoin the making ofburinw product.

The articles of manufacture embodying our invention-may be produced as follows:' Substantially pure tungsten powder is.

' pressed up into shapes or. forms such as disks, in a mold, as s own inF-igs. land 2,' which shapes or forms are then solidified by j heating process in a treating machine, as

as .illustrated therein or with electrodes as illustrated in Fig. 4. The disks so treated are then drilled or otherwiseshaped soas to make them suitable for use as wire drawing-'diesor for .jewels, and they are thenhardened in a specially. constructed hard- ,effect is produced through for dies orjewels,

' of 1.5 to. 25 tons er square inch is or completely, dependin desired to make ewe'ls or tain metals such .or. silica or their oxids may also be mixed with. thebone black desired to use the hardened products for certhe product ture .of carbon and boron, or carbon and titanium, or carbon and thoriu1n, or carbon and'silica', etc Inthis ,case the hardening external means and'can be varied by t e employment of difierenttemperatures 'and different durations of treatment, which treatment will cause thecementatiomboronizing or titaniz ing, etc., to take place either on the surfaces onlyjor throughout the mass.

It is preferablel to em loy substantially pure tungsten-powder pro uced by reduction of tungstic acid'with carbon or hydrogen.

theldisks into sizes suitable 'a;mold similar to that shown in Fig. 1' is employed and a pressure found to be sufficient. he-operation'of. solidify' ing these disks by baking and firing consists in bringing the disks slowly up to a temperature of approximately 1200 degreesfC. for aperiod of fifteen minutes either in a vacuum or-inan inert atmosphere and then toja temperature ofapprokimately'1600 degrees C. for another perio of fifteen minutes in the same way. then in a condition to be drilled partially upon whether it is scientific instruments or-watches, or, to make'dies for wire drawing. After the disks are drilled they are further hardene' between carbon or graphite electrodes. his step is very ea'siify In pressing up carried out by the use of a machine simil drilled tungsten die or jewel or a number of laced betweentwo carbon or them are, graphite -e ectrodes; They are then surrounded with a powder of charcoal on boneblack It as shown in Fig. 3. Usually for this purpose-we prefer to use bone black or a mixture of bone black and boric acid. Ceras boron, thorium, titanium orcharcoal when it istain definite purposes.

Anelectric current of 500 to 700 amperes white heat is obtained. As the hardening owder burns u .it 'is replenished with reshr powder. v hile an intense heat is always sufficient to maintain a carbonaceous atmosphere around s operated upon, yet in some cases we inclose the hardening head by a bell jar J, as illustrated in Fig. 7 "and surround the head with anatmosphere of carbon dioxid or carbon monoxid or some other en or nitrogen. are heldatthis inert atmosphere as hydro The products to be hardene These fired disks are is then conducted through these products 1.. 'and by this means an' intense white heat fora .period of ten to thirty In making dies which are to be used in 5 minutes, the period depending upon the degree of hardness desired and the depth of the hardened surface which we wish to obtain. If this step of heating the products to a white heat is continued for asufliciently' long period, the mass will be hardened throughout.

In order to attain disks ths"'in diameter and from 2 to f ths thick, which are suitable for use as wire drawing dies it is preferableto subject the products to the aforesaid white heat in the aforesaid'hard- .ening atmosphere for a period of ten to twelve minutes. 5-

'In cases where extreme hardness is de: sired we prefer to cool the dies quickly in a brine solution or in oil.

We have found that the products resulting from this process will easily scratch glass and approach the hardness of carborundum and diamonds. The hardened prodnot 'which may be used either'as' a Wire drawing die or as a jewel will then consist of an inner body of tungsten with a surface of tungsten carbid or tungsten borid, or

tungsten carbid and tungsten itanid, or tungsten carbid and thorium c rbid, etc., or mixtures thereof according to the materials originally employed. The hardened products are now finished off slightly and then spun into copper or mounted into steel, or any othersuitable mountings if they are to beutilized for dies for wire drawin or they are set into small metal holders i they are to be used for jewels.

.Our process may also be carried out by directly introducing the hardening ingredients in the proper proportions into the powdered tungstenmetal and then pressing the mixture into the desired sha e or form as disks or slugs. ,These' dis 5 or I slugs are then treated in our specially constructed treating headsuch as that shown in Figs.- 3, 5 and 7. Thesetreated slugs are then cut, ground or otherwise shaped into the desired forms or drilled to the desired size.

In all cases we employ substantially pure tungsten prepared by hydrogen or carbon reduetiom and as has been hereinbefore described the hardening agents may either surround the pressed up tungsten disks, as

shown in Fig. 3 and'thereby act from the outside, or a small percentage of the hardening agents, in powdered form such ascarbon and boron, or carbon and thoria, or'

carbon andtitanium, or carbon and iron, or or boron and 1ron, or boron and. iron and thoria, etc., maybe mixed with the tungsten powder and pressed upinto the disk as shown in Fig. a, or into the rod as shown in" 'hot wire drawing or in wire drawing at high temperatures we employ a mixture of-about the following proportions:

Tungsten 91 Iron. 6 Carbon 11% Thorla 2%75' Or'in'some .cases we use a mixture as follows:

Tungsten 92 Iron 1 6 Carbon &% a%

In making dies for cold wire drawing we 1 Recommend either of the following two mix- For the manufacture of material to be used for wire drawing dies we generally prefer to use the carbon reduced tungsten. The pressingup of the powdered material into the shapes shown in Figs. 3, 4, 5 and 7 is accomplished by means of the use of an ordinary pressing mold with a pressure of 15 to 30 tons per square inch. The bars weigh about 200 g., are approximately 8" long and a" square. slugs are placed into a firing furnace and subjected to a temperature of 1100 C. to 1200 C. for a period of 20 to 30'minutes while in an inert atmosphere or vacuum. By this means the slugs are strengthened and are then placed between electrodes and an electric currentis then sent through them, the slugs being surrounded by an atmos phere of hydrogen or by a carbonaceous'or inert atmosphere. If the mixture for the manufacture of dies to be used for the hot drawing of wire is used, .we send a current of about 1200 amperes through the slugs,

whereas if the mixture for'cold wire draw- After pressing, the

use a current of about 2200 amperes for this a purpose. The current is gradually increased so that the various ingredients in the bar are slowly sintered together to produce a homogeneous sintered mass. In either of the above cases the bar or slug is usually held at the maximum temperature for a period of 15 minutes. The treated slugis then cut into disks of any desired size, depending upon the use to which they are to be put. The cutting can be done by means of a thin carborundum or alundum cutting wheel re- In the manufacture of wire drawing dies,-

disks .thick and 35. in diameter are usually cut.

for jewels, the'rod is first rounded. off on. a

'-=carborundum wheel and it is then cut into disks of any desired thickness. These hardened tungsten disks are then spun into copper blanks'or' mounted in steelblanks by means of steel or brass. The mounted dies or the substitute jewels are: laced on automatic drilling machines an holes or'cups drilledthrough or into' them by means of tungstenor steel needles, using diamond dust or carborundum powder or tungsten carbid powderas an abrasive.

In order to obtain tools or instruments of various shapes or forms the tungsten metal powdenor mixture of powders is pressed into the desired shape and then treated in a treating outfit of suitable form built and arranged on the principles outlined above can he used either as a powder or with. some bindmg material shaped into any desired 7 for the manufacture'of disks for wire draw ing dies or for substitutes for jewels.

In the manufacture of an abrasive powder the material is first pressedinto rods, .cubes or forms of suitable size which are treated in accordance with the 'processhereinabove deserlbed. The material so/obtained is then crushed to the deslred fineness of rain and form, such as grinding wheels, razor hones, etc.

, We have-found it expedient in a few cases" to combine the external .and internal treatments to a certain=de'gree, that is, some of the harden ng materials may be introduced directly into the powdered tungsten and the I remainder used externally. k

T0, recapitulate, our invention contemplates the hardening of the material treated (a) by an external treatment, (b) b an internal treatment and "(0) by acombmed ex-. ternal and internal treatment.

I -Ewtemal treatment -Pure tungsten metal into a diskor slug,

powder is ressed u and this dis ,or slug is surrounded by a mixture of carbon. powder and. an oxid powder such as titanium oxid. When these materials are placed between electrodes and subcarbonaceous atmosphere is created by ieajected to ahigh temperature treatment, a

son of the presence of the carbon powder which surrounds the tungsten slug and this carbonaceous atmosphere acts upon the tu gi sten and producesthereupon a superficial layer oi ungsten carbid. Atthe same time the carbo ts upon the rare earth oxid thus causingap'artial reduction of the. same and the heat is sufiicient "to vaporize this 'par-- tially reduced same combine with the tungsten partiallymaterial. The vapors of the When the'material-is to be used.

fractory. L

.able for wire drawing dies or bringing the same to a alloying the surface of the same, and there is thereby produced on the tungsten metal an extremely hard surface. due to the com bined cementation and alloying.

Internal treatmnt.ln this case a disk powder with a small amount of powdered carbon and powdered iron and thoria. When this-slug is subjected to a high heat treat-' ment either in a reducing or' in an inert atthoria and iron and the carboncements the tungsten and iron producing carbide. The resulting product is extremely hard and -re' Combined ewtermzl mega-In the combined external and internal treatment we press up a slug formed of pure tungsten owder, iron powder, carbon powder and t oria powder and surround this pressed up s1 and oxid powder suc as boron oxid. When these materials are subjected to a high heat treatment the'body is hardened throughout amli yet the surface of the body is rendered sti l boronizing and carbonizing.

Molybdenum powder may be utilized in "or slug is formed by' pressing up tungsten mosphere, the tungsten combines with the and internal treatwith carbon powder harder due to the additional exterior 90.

the performance of our process or in the manufacture 'of .our products 1n the same relation to the use of tungsten powder.

.Having now described our invention, what we claim as new and desire to secure by Letters Patent is:

-manner as has been hereinabove described in 1. The processof hardening a refractory metal which conslsts in simultaneously producing a cementation of the said metal and an 'allo ing by high heat treatment. v

2. T e process of hardening refractory metals which consists in subjecting thesame 106 to 'a high heat in the another metal, there y producing vapors which cause cementation and alloying.

' 3. The rocess of hardening refractory resence of carbon and metals which consists in subjecting the same 110 to high heat in the presence of carbon, metal oxids and another mtahthereby simultaneously producing cementation, alloying, and a combining of the metals with the oxids.

4. The process of producing material suit- 11 in carbon.

5. The process of producing material suit-- able for wire drawing dies or as substitutes for jewels which consists in presslng powders of substantially pure refractory metals intoshapes, and hardening said shapes by white heat between as substitutes e same to a white heat between suitab eelectrodes while embedded Suitable electrodes while embedded in a powdered mixture oxid. i

6. The process of producing material suitable for wire drawing dies or as subst'i-f tutes for jewels which consists in pressing:

powders of substantially pure refractory metals into shapes, and hardening said shapes by bringing the same to awhite heat between suitable electrodes while embedded in a powdered mixture of carbon and a metal oxid.

7. The process of producing material suitable for wire drawing dies or as substitutes for jewels which consists in pressing powders of substantially pure refractory metals into shapes, and hardening said shapes by bringing the same to a white heat between suitable electrodes while embedded in a powdered mixture of carbon and a mixture containing powdered metalloid and powdered metal.

8. The process of producing material suitable for wire drawing dies or as substitutes for jewels which consists in pressing powders of substantially pure refractory metals into. shapes, and hardening said shapes by bringing the same to a white heat between suitable electrodes while embeddedin a powdered mixture of carbon, a metalloid and a rare earth oxid. i

9. The process of producing material suitable for wire drawing dies or as substitutes for jewels which.consists in pressing substantially pure powdered tungsten .metal into shapes, and hardening said shapes by bringing the same to a white heat'between suitable electrodes while embedded in a poyvldered mixture of carbon and a rare earth 0x1 v 10. The process of producing material suitable for wire drawing dies or as substitutes for jewels which consists'in' pressing substantially pure powdered tungsten metal into shapes, and hardening said shapes by bringing the same to a white heatbetween suitable electrodes while "embedded in a poygdered mixture of carbon and a metal 0x1 1 1. The process of producing material suitable for wire drawing dies or as substitutes for jewels which consists' in pressin substantially pure powdered tungsten meta v suitable electrodes while embedded in a into shapes, and hardening said shapes by bringing the same to a white heat between stitutes for jewels which consists in pressing substantially pure powdered tungsten metal into shapes, and hardening said'sha es. by bringing the same to a white heat eof carbon and a rare earth.

tween suitable electrodes while embedded in.

a powdered mixture of carbon, a metalloid and a rare earth oxid.

13; The. process of producing hard materials which consists inmixing a substan-' in a powder containing a mixture of carbon and rare earth oxid.

, 15. The process of producing hard materials which consists in mixing a substantially purerefractory metal'powder .with,a

powder containing carbon, pressing the mix-' ture into shapes, hardening tlie pressed shapes. by subjecting them to a white heat v between suitable electrodes while embedded,

in a mixture of carbon and metal oxid.

- -16. The process of producing hard materials which consists in mixing powdered tungsten metal' with a powder containing carbon, pressing the mixture into shapes, hardening the pressed shapes by "subjecting them to a white heat between suitab e electrodes while embedded; in a mixture of carbon and metal oxid.

17. The process of producing hard materials which consists in mixing powdered tungsten metal with a powder containingcarbon, pressing the mixture into shapes, and hardening the pressed, shapes by subject- .ing them to a white heat between suitable electrodes'whileembedded in a powder containin carbon.

'18-. he process of producing hard ma- 'terials which consists in mixing powdered tungsten metal with a powder containing carbon,'pressing the mixture into shapes, and hardening the jectin them to a w to heat between sultable e ectrodes while embedded in a powder containin a mixture of carbon and rare earth oxid. 1 19. The herein described product, which comprises an alloy of a refractory metal with a' base metal, and a carbid of said refracto'ry metal, said product containing approximately ninet partsof said refractory metal to not more thanabout one part of carbon.

20. The hereindescribed product, which comprises an alloy of a refractory metal with iron-and a carbid-of said refractory metal, said product containing approxiplj'essed shapes by sub mately'ninety parts of said refractory metal to not more than about one part of carbon. 21. vThe herein described product which comprises an alloy of tungsten with iron and a carbid of tungsten, said product containing approximately ninety parts of tungsten to not more than about one part of .carbon.

' 22. The herein described product, which comprises an alloy of a refractory metal with a base metal, a carbid of said refractory metal, and a'union of a metal of said alloy with an oxid of a .rare earth metal, said product containing approximately ninety parts of said refractory metal to not more than about one part of carbon.

23. The herein described product which comprises an alloy of a refractory metal with iron, a carbid of said refractory metal and a union of a metal of said alloy with a carbid of rare earth metal, said product containing approximately ninety parts of.

said refractory metal to not more than about one part of carbon.

24. The herein'described product which comprises an alloy of tungsten with iron, a carbid of tungsten, and a unionof the metal of said alloy with a carbid of rare earth metal, .said' product containing approximately ninety parts of tungsten to-not more I than about one part of carbon.

, 25. The/herein described product, which comprises an alloy of 'a refractory metal with a base metal, a carbid of-said refractory metal, and a union of the metals of said alloy with, an oxid of a rare earth metal, said product containing approximately ninety parts of said refractory metal to not more than about one part of carbon.

26. The herein described product which comprises an alloy ,of a' refractory metal with iron, a carbid of said refractory metal,

and a union'of the metals of said alloy with tungsten to not 'more an oxid of rare earth metalfisaid product containing approximately ninety parts of said refractory metal to not more than about one part of carbon.

27..The herein described product which comprises an alloy of tungsten with iron, a carbid of tungsten, and a union of the metals of said alloy with an oxid of rare earth metal, said product containing approximately ninety parts of tungsten to not more than about one part of carbon.

28. The herein described product, which comprises an alloy of a refractory metal 30. The herein I I a, described product which comprises an alloy of tungsten with iron,

a carbid of tungsten andan alloy of tungsten with a rare earth metal, said product containing approximately ninety parts of than about one part of carbon.

In witness whereof-we have hereuiito set our hands at the boropfgh of Manhattan,

ork, this 20th day city and State .ofNew of April, 1917. l

ALFRED'J. LIEBMANN. CLEMENS A; LAISE.

y In presence of- ISABEL R. RICHARDS, "ZITA M. GRAnAM. 

